A laser radar device, which generates three dimensional information of an area to be measured from a distribution of received light signals obtained by: irradiating an area to be measured with laser light while scanning the area to be measured with the laser light; and a light receiving element receiving reflected light from an object or the like that is preset in this area to be measured, has been generally known. A laser radar device of this type has a scanner provided in each of a laser light sending side and a reflected light receiving side, and causes reflected light to be incident on a light receiving element by adjusting, as required, a mirror angle (an acceptance angle of the reflected light) of the scanner at the light receiving side according to a mirror angle (a light sending angle of laser light) of the scanner at the light sending side upon scanning. Because of the provision of the scanners at both the light sending side and light receiving side, this configuration has had a problem that the laser radar device as a whole is increased in size.
In order to solve the above described problem, a laser radar device that is not provided with a scanner at a light receiving side thereof has been conventionally proposed (see Patent Literature 1). This laser radar device realizes scanlessness at the light receiving side while achieving a wide two dimensional visual field, by having: a long light receiving element array, which has long light receiving elements arrayed in a direction orthogonal to a long direction of the light receiving elements; a transimpedance amplifier array that amplifies received signals; and an adder circuit that adds together the received signals from respective elements of the transimpedance amplifier array.